9% ? I'm guessing you mean 9% of net profit, as I don't believe you can print and ship for 9%. You should specify what percent of gross sales the author actually gets, as it's not 93%
Indie authors sales these days are almost all ebooks. Actual indie physical book sales are tiny. Do you plan to generate ebooks?
Authors are notorious for sticking to their favorite writing tools. You might want to call out what import options you have.